(Washington Blade file photo by Michael Key)

COPENHAGEN — The mortality rate for men in same-sex marriages has dropped markedly since the 1990s according to a Danish study published recently in the International Journal of Epidemiology. Women in same-sex marriages, however, have emerged as the group of women with the highest mortality rates in recent years, the study found.

In 1989, Denmark implemented the world’s first national law on registered same-sex partnerships. For the first several years, the Journal reported, mortality rates for those in such marriages, were markedly elevated but since 1996 and the advent of effective anti-retroviral therapy for those with HIV/AIDS, mortality for men married to men has dropped to a level below that of unmarried men or divorced men.

Researchers attributed the higher mortality rates for women married to women to suicide and increased breast cancer risks for lesbians. Researchers at the Statens Serum Institut used Denmark’s Civil Registration System to follow 6.5 million adults who lived in Denmark for any period between 1982 and 2011.

Researchers said being married to or living with a member of the opposite sex resulted in the lowest mortality rates overall.